Помогите я прошу помогите пожалуйста! Use the present Perfect continuous and for or since for each of the following situations.

1. Dmitry started playing chess when he was 10 and he is still playing it. Dmitry has been playing chess since he was 10. 2. Victor began writing a letter to his pen-friend in the U.K. last week and he is still writing it. Dmitry has been writing a letter to his pen-friend in the U.K. since last week.